[windows] Implement center method #59

Author: lijy91

.vscode/settings.json

@@ -0,0 +1,14 @@
+{
+    "files.associations": {
+        "xstring": "cpp",
+        "map": "cpp",
+        "chrono": "cpp",
+        "functional": "cpp",
+        "optional": "cpp",
+        "system_error": "cpp",
+        "type_traits": "cpp",
+        "xlocmon": "cpp",
+        "xlocnum": "cpp",
+        "xtr1common": "cpp"
+    }
+}

example/lib/main.dart

@@ -17,6 +17,7 @@ void main() async {
       await windowManager.setTitleBarStyle('hidden');
     }
     await windowManager.setSize(Size(800, 600));
+    await windowManager.center();
     await windowManager.show();
     await windowManager.focus();
     await windowManager.setSkipTaskbar(false);

lib/src/window_manager.dart

@@ -210,8 +210,13 @@ class WindowManager {
     Map<String, dynamic> primaryDisplay = await _getPrimaryDisplay();
     print(primaryDisplay);
 
-    num visibleWidth = primaryDisplay['visibleSize']['width'];
-    num visibleHeight = primaryDisplay['visibleSize']['height'];
+    num visibleWidth = primaryDisplay['size']['width'];
+    num visibleHeight = primaryDisplay['size']['height'];
+
+    if (primaryDisplay['visibleSize'] != null) {
+      visibleWidth = primaryDisplay['visibleSize']['width'];
+      visibleHeight = primaryDisplay['visibleSize']['height'];
+    }
 
     Offset position = Offset(
       (visibleWidth / 2) - (windowSize.width / 2),
@@ -445,6 +450,7 @@ class WindowManager {
     final Map<String, dynamic> arguments = {
       'devicePixelRatio': window.devicePixelRatio,
     };
+    print(arguments);
     final Map<dynamic, dynamic> resultData =
         await _channel.invokeMethod('getPrimaryDisplay', arguments);
     return Map<String, dynamic>.from(resultData);

windows/window_manager.cpp

@@ -87,6 +87,8 @@ class WindowManager {
   double WindowManager::GetOpacity();
   void WindowManager::SetOpacity(const flutter::EncodableMap& args);
   void WindowManager::StartDragging();
+  flutter::EncodableMap WindowManager::GetPrimaryDisplay(
+      const flutter::EncodableMap& args);
 
  private:
   bool g_is_window_fullscreen = false;
@@ -579,4 +581,29 @@ void WindowManager::StartDragging() {
   SendMessage(GetMainWindow(), WM_SYSCOMMAND, SC_MOVE | HTCAPTION, 0);
 }
 
+flutter::EncodableMap WindowManager::GetPrimaryDisplay(
+    const flutter::EncodableMap& args) {
+  double devicePixelRatio =
+      std::get<double>(args.at(flutter::EncodableValue("devicePixelRatio")));
+  POINT ptZero = {0, 0};
+  HMONITOR monitor = MonitorFromPoint(ptZero, MONITOR_DEFAULTTOPRIMARY);
+  MONITORINFO info;
+  info.cbSize = sizeof(MONITORINFO);
+  ::GetMonitorInfo(monitor, &info);
+
+  double width =
+      (info.rcMonitor.right - info.rcMonitor.left) / devicePixelRatio;
+  double height =
+      (info.rcMonitor.bottom - info.rcMonitor.top) / devicePixelRatio;
+
+  flutter::EncodableMap size = flutter::EncodableMap();
+  size[flutter::EncodableValue("width")] = flutter::EncodableValue(width);
+  size[flutter::EncodableValue("height")] = flutter::EncodableValue(height);
+
+  flutter::EncodableMap display = flutter::EncodableMap();
+  display[flutter::EncodableValue("size")] = flutter::EncodableValue(size);
+
+  return display;
+}
+
 }  // namespace

windows/window_manager_plugin.cpp

@@ -348,9 +348,7 @@ void WindowManagerPlugin::HandleMethodCall(
   } else if (method_name.compare("getTitleBarHeight") == 0) {
     int value = window_manager->GetTitleBarHeight();
     result->Success(flutter::EncodableValue(value));
-  }
-
-  else if (method_name.compare("setSkipTaskbar") == 0) {
+  } else if (method_name.compare("setSkipTaskbar") == 0) {
     const flutter::EncodableMap& args =
         std::get<flutter::EncodableMap>(*method_call.arguments());
     window_manager->SetSkipTaskbar(args);
@@ -366,6 +364,11 @@ void WindowManagerPlugin::HandleMethodCall(
   } else if (method_name.compare("startDragging") == 0) {
     window_manager->StartDragging();
     result->Success(flutter::EncodableValue(true));
+  } else if (method_name.compare("getPrimaryDisplay") == 0) {
+    const flutter::EncodableMap& args =
+        std::get<flutter::EncodableMap>(*method_call.arguments());
+    flutter::EncodableMap value = window_manager->GetPrimaryDisplay(args);
+    result->Success(flutter::EncodableValue(value));
   } else {
     result->NotImplemented();
   }